What Comes Naturally
by SPICEGIRL97
Summary: Dean's captivated as Castiel's disheveled frame undresses. Dean can feel the Alpha in him growling lowly in approval as his eyes slowly rack top to bottom along Castiel's frame. Everything about him is just right. From the taunt muscular frame, to the creaminess of his skin, to the red flush along his cheeks and neck, to the lust in his eyes, to the omega's aroused scent in the air


What Comes Naturally

They say after one presents, their true mates scent acts as an insane aphrodisiac. As an alpha, Dean had never smelt an omega's scent that powerful. He considers himself easily enticed and well satisfied in just about every area (sex, money, booze etc.) As long as he's been a hunter, he'd never encountered anything or anybody that could make him _want_ on an subconsciously uncontrollable level.

However, he can't say he hasn't seen it before. He's seen plenty between his mother & father growing up. They'd have nearly violent arguments all the time and would make up as if it was nothing the very next day. He'd seen it with Sammie when he first found his mate, Gabriel, four months ago.

-4 Months ago-

They'd been on a hunt in Lakeview, Arkansas for another Shapeshifter. They had just stabbed the shapeshifter with silver when they turned the alleyway corner and Sam let out a giant groan of pain landing straight to the ground.

Instantly Dean had thought the shapeshifter had gotten a hit on him. When he had rushed over Sam was wheezing and panting. His face flushed. He remembered questing Sammie before he said he'd felt this...feeling. An urge. He couldn't explain it, but he had to follow it. Like he was being pulled and his body felt hot and extremely heavy. The closer they got Sam started to zone in more to his Alpha senses, tuning out Dean's questions and inquiries until they ended up out front a nearby bar.

"It's here."

"What?"

Dean had asked completely confused and insistent. He had not been expecting to get an answer. Sam yanked open the door and took a giant wiff of the air.

"There."

He says pointing towards the back of the bar near the restrooms. Right as they headed towards them, out popped a small omega with overgrown brown hair styled slick back along the sides of his face. He looked snarky, and young. He was small wearing jeans, and a light brown jacket. His eyes had instantly widened upon seeing them. Specifically Sam. Sam stepped forward almost tentatively to take a small wiff. The omega frowns.

"I wasn't expecting you to find me so easily."

The omega says grinning mischievously now. "You being a hunter makes sense though." He says looking between Dean & Sam.

Dean had frowned before looking down at him & Sam trying to understand what gave them away as hunters.

"Omega." Is all Sam mutters.

"Sammie, I don't understand," Dean huffed crossing his hands over his chest before pointing to the omega standing before them. "Who is this?"

"Sam, huh. As in _the_ Sam Winchester?" The omega questions as if not really expecting an answer at that moment.

Sam turns fully to Dean.

"He's my omega, Dean. My mate."

Dean's eyebrows had raised upon the information looking over the Omega as Sam walked over to him.

"Who would have thought I'd be mated to _the_ Sam Winchester!? This should be balls of fine in the future!" The omega mutters sarcastically staring up at Sam.

Later they learned the Omega's name was Gabriel the Archangel. They also learned that Sam is Lucifer's original vessel.

-Present-

It's been the whole rest of the year since Sam & Gab had gotten together, and Dean can't really say its for the better. Although Sam & Gab didn't argue like their parents did, they'd get into these snarky witty battering that drove Dean up the wall. Mostly because he could tell it was something they both secretly got off on, and Dean just didn't want to be around that shit. Gross. Particularly because their sexual tension gets worse around the times for Gabs heats or Sams ruts and Dean much rather liked taking up jobs solo during those times.

And this time he picked a job in small little city just a state over just in case one of them needed anything. He'd been in the middle of researching Lucifer's seals when he realized he hadn't eaten all day. Dean checks his phone seeing one voicemail. He grabs his keys and gets into his 67 Chevy while playing the phone message on the way to a diner.

" _Hey Dean. It's Sam. I need another few days with Gab. I'll call you again when we're ready."_

"A few days my ass!"

Dean rolls his eyes and tosses the phone onto the passenger seat before pulling up at Maggie's Diner. It isn't until he steps out of the car that he smells it. The scent was more than captivating. Intoxicating. It was refreshing in a calm earthy way, and subtly sweet with a pop of something rough and almost woodsy. What shocked him was the familiarity of the scent. Like he'd smelt traces of it somewhere before.

Not only does the smell get stronger as he strides towards the diner, his body's reaction to it becomes stronger. His body suddenly feels like lead as he places a hand onto the door handle. He's starting to break out into a sweat. Panting slightly as he uses his whole body to fling the door open. He's suddenly slapped in the face with the same scent he smelt before. Dean groans hunching over slightly with both his hands on his knees. He can smell his own scent reacting to the smell. He feels oddly aroused. He can feel himself slowly hardening beneath his jeans. Someone rushes over to him.

"Sir, are you ok?" A female voice laced with concern asks.

"Fine." He grunts out between clenched teeth.

"Let me help you." It's a female server wearing a diner uniform.

He allows the girl to drag him over to the bar table. Dean instantly covers his nose as the hairs of his body stands tall and he turns to his left.

On his left is the source of the scent. Only mere inches away from each other. Hunched over a half eaten burger is an omega with short black messy hair and the bluest eyes Dean had ever seen. His lips are parted in shock as he meets Dean's gaze. He wears a suit with a light brown trench coat and is already staring at Dean as if he's seen a ghost.

"It's you." They say at the same time. Dean inwardly groans at the gravely sound of the Omegas voice. His body instantly pulses with arousal.

"God, you smell divine."

Dean says before he can catch it. The omega stares openly before flushing and finally breaks eye contact. He shifts uncomfortably in his seat as his deep blue eyes drop downward subconsciously. It's the complete wrong direction to look because he instantly spots the growing tent in Deans jeans. It's Dean's turn to blush.

"Look buddy, I don't mean to offend you but I'm not entirely sure what's going on with me either."

"You're-We're Bonding." Says the omega nearly breathless. It's then that Dean notices the heavy flush along his neck and cheeks, the thin layer of sweet and the slight panting. He's hunched slightly and winces every once in awhile.

"Are you ok?" Dean points out leaning in closer. Before lifting a hand and cupping one of the omegas flushed cheeks.

The omega's eyes flutter closed as he instantly whimpers, leaning into the touch slightly. Not that they could get much closer to each other, but something just keeps pulling Dean to the man.

"Y-You gotta take me out of here before…" The words are lost on the omega as his eyes snap open wide and he bites down on his lip hard, repressing a long drawn out moan. The sound and the look on his face sparks a flame in Dean that tugs on his erection.

"Yea, ok." Dean agrees as he orders some food to-go before helping the omega to his car.

"What's happening? Who are you?" Dean questions in the car as they head back to his motel room. The omega becomes restless as he begins to strip off his trench coat and stretch out his limbs as if fighting some internal battle with himself.

"Name...Castiel...We're...mates." He mutters beginning to scratch at his skin.

"What!?" Dean shouts in shock as his own scent sparks. He's pulling up in front of the motel now, parking the car as Castiel begins to mutter something under his breath. From the corner of his eye Dean can seen Castiel squirming restlessly in the seat.

"I have to- I have to-" The omega doesn't finish the sentence. And when Dean looks over to the passenger seat, the omega is shivering with his eyes shut tight with his mouth open.

" _Oh!_ " He moans and instantly Dean's eyes widen as he takes in a wiff. A burst of arousal explodes in his senses and somehow Dean just knows. He just knows that this beautiful omega had an orgasm in the passenger seat of his Baby.

 _God that was hot._ Dean thinks, re-envisioning the scene as he feels his dick twitch in his pants. He's never been so shocked and turned on at the same time before. Dean sits there for a second, mouth hanging open and eyes drawn to the omegas lap. Which is now a mess, with prominent tent sticking out.

"Can we…" The omega says shakily snapping Dean out of his trance. Dean already mentally slapping himself for being so transfixed at the scene before him.

"Uh Yea, ok." Dean mutters getting out of the car. He helps the omega out and they stumble into the motel room together.

"I'm sorry about-" The omega starts to say turning to face Dean just as Dean does the same.

Their faces only centimeters apart. Dean doesn't think. Instead he closes his eyes and captures the lips of the Omega. He savories the feeling of the moist lips against his chapped ones and the thrill he gets from the omega reciprocating. The omega pushes forward turning the kiss from smooth to aggressive and needy. Dean grunts before nipping at the Omegas bottom lip. The omega whines as he begins to shed his clothing.

"Need. I need..." The omega says pulling at Deans clothing.

Dean parts from the kiss to strip off his jacket and flannel shirt as the omega drops his trench coat on the floor and strips from his suit jacket. Dean reaches forward and pulls the omega back towards his body. He takes hold of the white button down dress shirt and rips it in half like paper. Buttons flying all over the place but no one seems to care. The omega reaches forward and grabs hold of Dean's belt buckle. Dean grunts as he staggers placing wet kisses along the omegas neck. Taking in deep inhales of the omegas scent, grunting harshly as the omega dips his hands into his pants.

"Christ!" Dean grunts as the weight of his arousal bares down on him.

"Wrong. My name is Castiel." The omega says pulling down Deans pants, before pushing him backwards onto the bed.

"Castiel." Dean repeats watching as Castiel's disheveled frame undresses the rest of his clothes. Dean can feel the Alpha in him growling lowly in approval as his eyes slowly rack top to bottom along Castiel's frame. Everything about him is just right. From the taunt muscular frame, to the enticing creaminess of his skin, to the red flush along his cheeks and neck, to the lust in his eyes, to the omega's aroused scent in the air.

"And you're Dean Winchester." He says walking towards Dean who simultaneously leans back on the bed until Castiel's climbing on top of him.

"How do you know that?" Dean asks breathless as Castiel keeps a few inches distance between their faces.

"I'm an Angel of the Lord. It's my job to know who you are." He confesses glancing from Dean's forest green eyes down past Dean's compact muscles to the black briefs that cover the massive erection hiding beneath it.

"An Angel!?" Dean asks blinking in slight confusion.

"Yes Dean," A smile creeping up onto Castiel's lips as he stares at Dean, "Are you going to be shocked about everything I tell you about me?"

A little playful glint of light shining in his eyes letting Dean know he's inwardly laughing at him. Dean flushes and rolls his eyes.

"Oh shut up." Dean says before grabbing hold of Castiel and flipping him over.

Their make out session starts up once again and this time hands actually make contact with skin. It's hot and messy but neither of them would have it any other way. Cas drags his hands down Dean's back as he parts his legs letting Dean settle between them. Both emit harsh grunts as their erections brush against each other. Cas scratches at Deans boxers, and Dean hunches over Cas so Cas can slide them off. Neither break eye contact as the fabric slides off Deans legs. Their gaze on each other intense and knowing.

"I've never been with an Alpha before Dean." Cas confesses before Dean brushes a hand along Castiel's hip causing a full body shiver from Castiel.

Dean's inner Alpha couldn't be any more pleased with the news. Dean himself was only a little shocked. Someone as handsome as Castiel had never pulled an Alpha before him?

"I have a feeling this will come naturally," Dean mutters distractedly, lifting Castiel's right leg towards his shoulder effectively opening him up a little. Dean nearly huffs at how easily flexible Castiel is. _A beautiful omega._ Dean thinks as his Alpha purrs in approval, eyes dropping to Castiel's overly-slicked, ready and loose rim. _Just gorgeous._

"Dean." Castiel mutters eyes wide. Dean glances upwards seeing a flash of concern in Castiel's eyes. Dean frowns, not wanting Castiel to feel uncomfortable.

"Cas, You're basically going into heat right now. I smelt it the moment I pulled up at the diner," The information making Cas look away in embarrassment, yet Dan continues. Leaning forward until he's brushing their lips together. "And you're heat is triggering my rut. I don't think I'll be able to hold back."

Castiel pulls from the kiss to see Dean's forest green eyes nearly swallowed up by his pupils. He's panting, with his muscles flexing. Cas's eyes trail down Dean's sculpted wider frame, hesitating at the twitching flesh of meat standing tall and proud between Dean's legs. Castiel gulps as his eyes avert to the side.

"Ok Dean." Castiel says.

Dean swoops in attacking Castiel's neck before lifting Cas's other leg so he's spread open. He licks just along Cas's scent gland causing the Angel to shiver and moan as Cas takes hold of Dean's face for a lip lock. Their tongues battle for dominance which Dean wins easily getting caught up in the fight as well as the taste of the strawberry juice flavor Cas was drinking at the diner.

"Cas." Dean mutters as his head drops kisses until he reaches Cas's slicked entrance.

"Dean- Ah!" Cas moans completely caught off guard when Dean licks along the rim.

Dean savors the taste as a wave of arousal racks mercilessly through his body.

"God, You're delicious." Dean mutters more so to himself before placing both hands on the backs of Cas's thighs, keeping his open as he laps at Cas. Cas begins to squirm and move as moans are ripped right from his mouth.

"Dean. Dean!"

Cas's body clenching as Dean's tongue causes Castiel's body to slick and his toes to curl in ecstasy. Dean rubs at Cas's oversensitive inner thighs before taking a gentle hold of Castiel's fully hard dick.

" _Dean!_ "

Castiel nearly screams as his body arches and his fingers catch around the sheets. Dean glances over Castiel's form just in time to catch his face. Eyes screwed shut, mouth dropped into the perfect O, and a light trail of drool along Castiel's wet lips. Castiel cums hard. His body ruptures as he struggles to breath.

Dean huffs right along with his new lover. His throat had never been so dry. His dick throbbing wildly as his body is starting to tremble with need for the beautiful creature before him. The Alpha in him barely containing it's demand to pounce.

"Cas." Dean mutters hoping he can convey the desperation in his hoarse voice as it cracks uttering his lovers name.

Cas's eyes snap open revealing those ocean blues to Dean. He ignores the way they make his heart skips a beat every time he meets Cas's eyes. Except right now they're different. The raging ocean blue eyes have darkened and dazed from lust.

"Alpha." Cas acknowledges eyes sharp.

Before Dean can utter anything else Cas wraps his legs around Dean and flips them over. He takes hold of Dean's hands and raises them above Dean's head. Dean huffs, but Cas captures his lips into a kiss. Somehow there's more persistence than before and something about that has Dean pulsing harsher than earlier. Cas interlocks their fingers and then settles his weight right against Dean's hips, aligning them against each other.

"Shit!"

Dean grunts squeezing Cas's hand involuntarily as his hips buck.

"More."

Cas purrs into Dean's ear before licking against Dean's scent gland, one hot hand burning a trail down from Dean's shoulder, down his chest towards his pelvis until it stops along Dean's masculine thigh.

Dean lets out a shuttered breath as his heart is going wild in his chest anticipating Castiel's next location. And even though he knew, nothing could've prepare him when Cas grabs hold of his penis. A thin hand clasping with just enough pressure to make Dean's body jolt.

"Nuggh!" Dean grunts. "C-Cas." He stutters, one hand still gripping onto Cas while the other is digging into Cas's hip.

"Don't worry Dean," Cas purrs licking at Dean's ear, which he's found to be a huge sensitive spot for Dean going by the leaking precum from Dean's tip and the way he shivers and tries to wince away from the sensation. "I've got you."

At that, Cas positions his hips right above the throbbing appendage. Dean borderline whimpers at the feel of his tip coated in Cas's slick. Cas moans vocally as he briefly indulges in the feel of rubbing himself against Dean.

"Cas...Don't tease me." Dean warns sharply.

Cas huffs out a small chuckle before taking Dean into him. Dean hunches forward involuntarily as a groan is ripped from within. Both hands digging into Cas now as Dean steadies his hips, trying not to cum at the feeling of being completely engulf in hot wetness. Dean's body on fire as he struggles to contain his pleasure. Cas lets out a hiss between gritted teeth. God, Dean was well endowed for an Alpha let alone a human. He feels the lovely stretch as his body struggles to accommodate Dean's size.

"Fuck, Cas. Please move." Dean mutters panting heavily. Cas doesn't need to be told twice. He moves his hips experimentally; biting his lip at the drag of Dean's penis inside him before slamming back down. A grunt slipping through as Dean hits the back of him.

Dean reaches up and catch Cas's lips, because if he has to listen to Cas be any more vocal he knows he won't make it. Dean's knot is already beginning to form. Their chemistry is too strong. He's due any moment.

Cas gets into a rhythm that has both of them in a frenzy. Hips pumping, lips swollen, wet sloppy noises in the air, thin layer of sweat and the smell of sex heavy in the air. Cas rides Dean not missing a single beat as he gets all the angles just right. Dean takes hold of Cas's leaking penis, pumping in time with their rhythm.

"Dean. Dean!" Cas mumbles reach his limit. Thighs quaking against Dean's hips as they both nearly reach the edge.

"C...Cas" Dean's voice hoarse laced with desperation as his body is strung tight like live wire.

"Now Dean! Bite me, now!" Cas shouts, hitting his own prostate one last time, arching his back and canting his hips forward. Dean surges forward and latches onto Cas's scent gland just as Castiel cums emitting a drawn out orgasmic moan. He burst along Dean's sweaty abs. His cum hot as it makes contact. One, two, three thrusts and Dean's knot pops into Cas's loose rim just as he feels Cas convulses powerfully around his dick. Dean feel a gush of scorching slick burst around him as he's clenched so tight it momentarily takes his breath away.

Then he's gone. Dean's soul feeling like it's leaving his body as he lets go. Cas opens his eyes in time to see it. Dean's face scrunches up tight as he explodes in long thick ropes of cum gushing from his body. His hips staggering in rhythm as every muscle in his body flexes. His breath pulled into a completely wrecked gasp. Cas's name falling off his lips in abandonment. Cas couldn't help but stare in awe at this human. His mate.

And when they settled, Dean doesn't open his eyes immediately. He takes his time, and when those green eyes open they meet blue ones. A small smile is on Cas's lips.

"Hi Dean." Cas says still straddling Dean.

"Cas." Dean says roughly before shifting them into a better position.

"You were amazing for your first time." Dean mumbles giving small kisses along Cas's pale skin. He doesn't see Cas's smile. But he does feel his hole clench around his overly sensitive dick, eliciting a smaller orgasm from Dean.

"Well you were right, it did come naturally." Cas confesses pressing back into Dean's touches.

-FIN-


End file.
